ABSTRACT
<p><b>OBJECTIVE</b>To study the protective effect of an extract of Guipi Pill () against radiation-induced damage.</p><p><b>METHODS</b>A total of 100 Kunming mice were randomly divided into normal group, model group, positive drug group (treated with radioprotective agent "523", 5 mg/kg at 24 h before irradiation) and two treatment groups, with 20 mice in each group. The extract of water extraction-alcohol precipitation (WAP) from Guipi Pill were administered orally to the mice in the two treatment groups at the dose of 500 and 1,000 mg/kg, respectively, for 6 days prior to whole body radiation (8 Gy). Fifty mice with 10 in each group were used to observe the survival rate 30 days after radiation. The other 50 mice with 10 in each group were sacrificed on day 10 after radiation (6 Gy) in order to take blood, liver and unilateral femur.</p><p><b>RESULTS</b>Pretreatment prior to irradiation with WAP resulted in a significantly higher 30-day survival rate of mice after exposure to a potentially lethal dose of 8-Gy radiation. WAP could significantly increase the total white blood cell count and DNA content of bone marrow, and it also increased the activity of various antioxidant enzymes, such as superoxide dismutase, catalase, total antioxidant capacity and glutathione peroxidase in liver tissue of mice, which were reduced by radiation treatment. Maleic dialdehyde level and bone marrow micronucleus rate were significantly reduced by WAP, which were increased after 6-Gy radiation.</p><p><b>CONCLUSION</b>WAP of Guipi Pill could increase the 30-day survival rate and the antioxidant capacity as well as protect bone marrow in mice. WAP of Guipi Pill is an effective radioprotective agent.</p>